1. Field of the Invention
The present invention relates to methods and apparatuses for loading bulk material into containers. More particularly, the invention relates to methods for loading scrap metal and steel into freight containers, and apparatuses thereof.
2. Description of the Related Art
Efficiency and speed are important in the freighting industry. Decreasing the time necessary to load material into a freight container, transport the container, and unload the material from the container usually translates into greater profits for those involved in the process. One way the industry has increased efficiency has been to standardize the sizes of its freight containers, as defined by the ISO 668 standard. The use of standard sized freight containers allows tractor-trailers, ships, trains, and other freight carriers to quickly load and unload containers and to optimally utilize their available space. While freight containers come in several standard sizes, the most common sizes are the standard 40′, the 40′ high-cube, and the standard 20′. The minimum internal height of most ISO standard shipping containers is 7′ 8½″, while the minimum internal width is 7′ 7¾″.
The use of such standard internal minimum dimensions generally permits quick loading and unloading of standard sized pallets onto freight containers while maximizing the use of available space in the containers. Not all materials, however, are suitable for palletization. For instance, bulk material, such as scrap metal, generally should not be palletized because such material varies widely in shape. As a result, many pieces of the bulk material are too large to fit within a pallet and must be either loaded separately into the container or cut into smaller pieces. Even when the bulk material is small enough to fit within a pallet, the space in the pallet is generally severely underutilized because of the bulk material's irregular shape. Because of the problems associated with palletizing bulk material, other methods for loading bulk material into freight containers have been developed.
One method to load bulk into a freight container is to use a conveyer belt. In this way, bulk material is placed on a conveyer belt that leads from outside of the container, through a door in the container, and terminates at an opposite closed end of the container. When the material reaches the end of the conveyer belt, it falls off the belt and is thus placed in the container. There are several problems with this method. First, the size of the conveyer, coupled with the irregular shaped bulk material, makes it difficult to utilize a high percentage of the available space in the container; there simply is not enough clearance in the container to permit stacking bulk material beyond a certain height. Also, the size of the bulk material, particularly Heavy Melting Scrap (“HMS”), is often too large to be properly transported using the conveyer belt, requiring the bulk material to be further shredded or otherwise reduced in size before being loaded. Moreover, it is not uncommon to have irregularly shaped pieces of material to impact with the sidewalls of the container while being loaded. Such impacts can severely damage the sidewalls, which are generally very thin. Such impacts are especially common when loading HMS.
Another method to load bulk material into a freight container is to use a skid loader. When using a skid loader, the bulk material is carried into the container and then dumped in place. This method is also less than satisfactory. Errors in operation of the skid loader can lead to physical injuries to workmen, and can also easily damage the sidewalls and ceiling of the container. Also, only small skid loaders can be used because of the relatively small size of the containers in which they are to operate. The use of small skid loaders requires operators to make numerous trips between the bulk material pile and the freight container. Furthermore, because the skid loader operates by lifting its bucket and then dropping its load, it is impossible to load material above a certain height within the container, decreasing the effective utilization of the container.
U.S. Pat. No. 7,172,382 to Frankel (“Frankel”), discloses an additional method and apparatus for loading bulk material into a freight container. Frankel discloses a loading assembly including a support structure, a load bin having a cross section conforming to an open end of a container, and a drive mechanism configured to urge the load bin into and out of the container. When fully inserted, the contents of the load bin are disposed within the container. The loading assembly further includes a barrier configured to keep the load confined within the container while the load bin opens to allow the load to remain within the container upon retraction of the load bin. The barrier projects above the top of the load bin to follow the frame of the support structure, and is not inserted into the container. The device disclosed by Frankel is unsatisfactory, as it is overly complicated and expensive. It has numerous moving parts and drive mechanisms which are susceptible to failure, requiring costly repairs and decreasing loading efficiency.
Thus, better apparatuses and methods for loading bulk material into freight containers are needed.